Import wiredtiger: 9347af9cb5271855cbea7719f1b57bfe94621912 from branch mongodb-5.2

ref: df8173e949..9347af9cb5
for: 5.2.0-rc5

WT-7236       Cache the result of the wiredtiger_crc32c_func() return value

5 files changed, 53 insertions, 19 deletions

diff --git a/src/third_party/wiredtiger/import.data b/src/third_party/wiredtiger/import.data
index e531f95769b..e4df97c78ba 100644
--- a/src/third_party/wiredtiger/import.data
+++ b/src/third_party/wiredtiger/import.data
@@ -2,5 +2,5 @@
     "vendor": "wiredtiger",
     "github": "wiredtiger/wiredtiger.git",
     "branch": "mongodb-5.2",
-    "commit": "df8173e94998ddd53638f68e9f6fb858f25f5648"
+    "commit": "9347af9cb5271855cbea7719f1b57bfe94621912"
 }
diff --git a/src/third_party/wiredtiger/src/checksum/arm64/crc32-arm64.c b/src/third_party/wiredtiger/src/checksum/arm64/crc32-arm64.c
index 3ca1dfed4ba..de13cd6878b 100644
--- a/src/third_party/wiredtiger/src/checksum/arm64/crc32-arm64.c
+++ b/src/third_party/wiredtiger/src/checksum/arm64/crc32-arm64.c
@@ -100,13 +100,24 @@ extern uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t);
  */
 uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t)
 {
+    static uint32_t (*crc32c_func)(const void *, size_t);
 #if defined(__linux__) && !defined(HAVE_NO_CRC32_HARDWARE)
-    unsigned long caps = getauxval(AT_HWCAP);
+    unsigned long caps;
+#endif
+
+    /*
+     * This function calls slow hardware functions; if the application doesn't realize that, they
+     * may call it repeatedly rather than caching the result.
+     */
+    if (crc32c_func != NULL)
+        return (crc32c_func);
 
+#if defined(__linux__) && !defined(HAVE_NO_CRC32_HARDWARE)
+    caps = getauxval(AT_HWCAP);
     if (caps & HWCAP_CRC32)
-        return (__wt_checksum_hw);
-    return (__wt_checksum_sw);
+        return (crc32c_func = __wt_checksum_hw);
+    return (crc32c_func = __wt_checksum_sw);
 #else
-    return (__wt_checksum_sw);
+    return (crc32c_func = __wt_checksum_sw);
 #endif
 }
diff --git a/src/third_party/wiredtiger/src/checksum/x86/crc32-x86.c b/src/third_party/wiredtiger/src/checksum/x86/crc32-x86.c
index 266f56d4cc3..a96b793cee3 100644
--- a/src/third_party/wiredtiger/src/checksum/x86/crc32-x86.c
+++ b/src/third_party/wiredtiger/src/checksum/x86/crc32-x86.c
@@ -124,16 +124,28 @@ extern uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t);
  */
 uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t)
 {
+    static uint32_t (*crc32c_func)(const void *, size_t);
 #if !defined(HAVE_NO_CRC32_HARDWARE)
 #if (defined(__amd64) || defined(__x86_64))
     unsigned int eax, ebx, ecx, edx;
+#endif
+#endif
+
+    /*
+     * This function calls slow hardware functions; if the application doesn't realize that, they
+     * may call it repeatedly rather than caching the result.
+     */
+    if (crc32c_func != NULL)
+        return (crc32c_func);
 
+#if !defined(HAVE_NO_CRC32_HARDWARE)
+#if (defined(__amd64) || defined(__x86_64))
     __asm__ __volatile__("cpuid" : "=a"(eax), "=b"(ebx), "=c"(ecx), "=d"(edx) : "a"(1));
 
 #define CPUID_ECX_HAS_SSE42 (1 << 20)
     if (ecx & CPUID_ECX_HAS_SSE42)
-        return (__wt_checksum_hw);
-    return (__wt_checksum_sw);
+        return (crc32c_func = __wt_checksum_hw);
+    return (crc32c_func = __wt_checksum_sw);
 
 #elif defined(_M_AMD64)
     int cpuInfo[4];
@@ -142,12 +154,12 @@ uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t)
 
 #define CPUID_ECX_HAS_SSE42 (1 << 20)
     if (cpuInfo[2] & CPUID_ECX_HAS_SSE42)
-        return (__wt_checksum_hw);
-    return (__wt_checksum_sw);
+        return (crc32c_func = __wt_checksum_hw);
+    return (crc32c_func = __wt_checksum_sw);
 #else
-    return (__wt_checksum_sw);
+    return (crc32c_func = __wt_checksum_sw);
 #endif
 #else
-    return (__wt_checksum_sw);
+    return (crc32c_func = __wt_checksum_sw);
 #endif
 }
diff --git a/src/third_party/wiredtiger/src/checksum/zseries/crc32-s390x.c b/src/third_party/wiredtiger/src/checksum/zseries/crc32-s390x.c
index dfa1d9e03b2..8db4b254366 100644
--- a/src/third_party/wiredtiger/src/checksum/zseries/crc32-s390x.c
+++ b/src/third_party/wiredtiger/src/checksum/zseries/crc32-s390x.c
@@ -106,14 +106,25 @@ extern uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t);
  */
 uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t)
 {
+    static uint32_t (*crc32c_func)(const void *, size_t);
 #if defined(__linux__) && !defined(HAVE_NO_CRC32_HARDWARE)
-    unsigned long caps = getauxval(AT_HWCAP);
+    unsigned long caps;
+#endif
+
+    /*
+     * This function calls slow hardware functions; if the application doesn't realize that, they
+     * may call it on every request.
+     */
+    if (crc32c_func != NULL)
+        return (crc32c_func);
 
+#if defined(__linux__) && !defined(HAVE_NO_CRC32_HARDWARE)
+    caps = getauxval(AT_HWCAP);
     if (caps & HWCAP_S390_VX)
-        return (__wt_checksum_hw);
+        return (crc32c_func = __wt_checksum_hw);
     else
-        return (__wt_checksum_sw);
+        return (crc32c_func = __wt_checksum_sw);
 #else
-    return (__wt_checksum_sw);
+    return (crc32c_func = __wt_checksum_sw);
 #endif
 }
diff --git a/src/third_party/wiredtiger/src/include/wiredtiger.in b/src/third_party/wiredtiger/src/include/wiredtiger.in
index f3223141e77..b8ac1cbbfdc 100644
--- a/src/third_party/wiredtiger/src/include/wiredtiger.in
+++ b/src/third_party/wiredtiger/src/include/wiredtiger.in
@@ -3663,13 +3663,13 @@ struct __wt_config_parser {
 /*!
  * Return a pointer to a function that calculates a CRC32C checksum.
  *
- * The WiredTiger library CRC32C checksum function uses hardware support where
- * available, else it falls back to a software implementation.
+ * The WiredTiger library CRC32C checksum function uses hardware support where available, else it
+ * falls back to a software implementation. Selecting a CRC32C checksum function can be slow, the
+ * return value should be cached by the caller for repeated use.
  *
  * @snippet ex_all.c Checksum a buffer
  *
- * @returns a pointer to a function that takes a buffer and length and returns
- * the CRC32C checksum
+ * @returns a pointer to a function that takes a buffer and length and returns the CRC32C checksum
  */
 uint32_t (*wiredtiger_crc32c_func(void))(const void *, size_t)
     WT_ATTRIBUTE_LIBRARY_VISIBLE;